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[Bug 1489292] Re: System cannot detect USB device in BAT mode


** Changed in: hwe-next
   Importance: Undecided => Critical

** Changed in: hwe-next
     Assignee: (unassigned) => Phidias (phidias-chiang)

** Changed in: hwe-next
       Status: New => Triaged

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  System cannot detect USB device in BAT mode

Status in HWE Next:
Status in linux package in Ubuntu:

Bug description:

  On some Skylake-U platforms, if boots with battery only and has no USB
  device connect, after boot the USB port can't be used, even though the
  xHCI Host Controller doesn't report any error in dmesg. The USB device
  looks like doesn't turn on, LED on USB mouse or keyboard doesn't light


  There's a fix in mainline v4.2-rc3, though it states the fix is for
  Braswell, but the uuid use in the commit can also be found on
  Skylake-U platforms.

  Commit log is as follows:

  commit c3c5819a350952439c3198aa46581f9e4c46557f
  Author: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
  Date:   Tue Jul 21 17:20:25 2015 +0300

      xhci: call BIOS workaround to enable runtime suspend on Intel

      Intel xhci hw that require XHCI_PME_STUCK quirk have as default disabled
      xhci from going to D3 state in runtime suspend. Driver needs to verify
      it can deal with the hw by calling an ACPI _DSM method to get D3 enabled.

      Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
      Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>


  1. Install the patched kernel
  2. Boot with battery
  3. Insert a USB device (disk, keyboard, mouse), should work normally

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